29 U.S. Code § 1027 - Retention of records

Every person subject to a requirement to file any report (including the documents described in subparagraphs (E) through (I) of section 1021(k) of this title) or to certify any information therefor under this subchapter or who would be subject to such a requirement but for an exemption or simplified reporting requirement under section 1024(a)(2) or (3) of this title shall maintain a copy of such report and records on the matters of which disclosure is required which will provide in sufficient detail the necessary basic information and data from which the documents thus required may be verified, explained, or clarified, and checked for accuracy and completeness, and shall include vouchers, worksheets, receipts, and applicable resolutions, and shall keep such records available for examination for a period of not less than six years after the filing date of the documents based on the information which they contain, or six years after the date on which such documents would have been filed but for an exemption or simplified reporting requirement under section 1024(a)(2) or (3) of this title.